Hobbyking X-car motor issues

[stingeragent]

Ok, so I apparently jynxed myself by talking up HK in a different thread, but anyways. Been running an x-car sensored motor and 60a sensored x-car esc for last couple days. Has been running great. Tonight, I was going up a slow climb and it just gave out on me. I assumed the lvc had kicked in, so I charged up my lipo but it only put 300 out of 4000 back into the pack so I realized that wasn't the issue. Plugged it back in, and same thing. Only now the motor no longer beeps. Esc still initializes. I have steering. In sensored mode, if I manually kick the truck be it forward or back, as long as I have some throttle on it will go until I stop. But as soon as I stop, I have to push it again to get it going. I unplugged the sensor cable, and it goes from a stop no problems but for some reason I have no reverse. Even if I kick it backwards it doesn't go. Originally I had an issue getting one of the wires to stay soldered to the tab, but I can't see that being the issue as it's working perfectly fine sensorless (minus reverse), and it works sensored if I push the truck. It seems if I had a bad solder joint it wouldn't run period be it sensored, or sensorless. When all this happened I had only been driving the truck for like 45 secs so I can't see it having over heated. I pulled the sensor cable and flipped it, and made sure both sides are plugged in good and still same problem. This being my first sensored motor, I have no clue. I've either got a bad motor, bad sensor board, bad sensor cable, or bad esc. I just can't figure out which sense if I push the truck in sensored it works no problem unless I stop. Any ideas?

[Eric0424]

A weak solder joint can cause erratic motor and ESC behavior, a bad joint won't necessarily result in a total failure. I've had some that were fine until the car/truck crashed, after unplugging the battery and plugging it back in or wiggling the motor wires and it would run fine until the next hard knock. I re-soldered those connections and it was fine. It takes more current to get a motor started than it does to keep it moving after it's spinning, so that weak joint may not be getting the current to the motor. Reverse in one mode but not the other is odd, but could also be caused be the solder joint.

I would start with with fixing the solder joint and triple checking the others, then look at the sensor cable and price a new sensor board for the motor. If you have access to another ESC and motor it would help diagnose the problem.

[stingeragent]

Well I have plenty of esc's, and motor's around but they are all sensorless so that won't help me much. I did fix the solder joint on the 1 wire, but tomorrow I'm gonna pull off all 3 wires, get a new soldering iron, and redo all 3 just to eliminate that as the cause. I really don't think it is, but the price of a new soldering iron will be cheaper than a new motor or esc. I thought the no reverse was weird also. I recalibrated the throttle in sensored, and sensorless and it made no change so I'm not sure. Since I went cheap which may or may not be my problem, I don't think they sell replacement boards, and if they do will probably be cheaper to buy a new cheap motor. I've had good luck with HK in the past so I'm gonna hope its my soldering skills. Will update tomorrow after I redo that.

[stingeragent]

Ok, so I took the truck apart. Redid all my solder joints and now they are on rock solid. I decided to pull the motor can apart to make sure nothing looked fried on the sensor board, so got it all out and didn't see any problems. Put everything back together, and same issue. I then got to wondering. Does the sensor board have to be rotated a certain way or does it matter? This motor doesn't have adjustable timing on the can itself but it can be changed in the esc. Looks like I'm stuck pulling it all back apart to make sure the board is in there right.

[drzoo2]

I use the 80 amp version and had exactly the same issue on a brand new esc. After recalibrating it, I haven't seen the issue thus far. If it returns, the esc is going on my scope to see what's up. For me, just jiggling the servo was enough to get it to move. I built a light controller that samples the output of the receiver so I know there was signal .

I'm interested to see if after you recalibrate, it also fixes it.

[Eric0424]

The sensored motors I have are either fixed timing and the sensor board has just one position or they're adjustable but still have just one position for the sensor board, although they can be moved about 40° from that spot depending on the motor.

If you're not sure about location see if the pictures at Hobby King show you the original position.

[stingeragent]

Ok, well I ripped it all back apart and I'm dumb. The board is screwed to the top cap so theres only one way it can go to match up with the screw holes. I'm getting really quick at pulling this motor out. Anyways, I was doing some testing, and I went through every possible setting, throttle trim, timing, motor reverse, radio throttle reverse, drag brake, etc, and recalibrated it each time. I can now get it to move from a start. I have to push it forward. Once I come to a stop, as long as I don't hit reverse it will go forward again albeit with terrible cogging. If I hit reverse after I stop, it then won't go forward again, and still won't go back. I have recalibrated it about 20 times over the last hour and it's just broke. Examined the sensor board again real close and all solder joints are intact. No blown fet's or whatever there called. It should be working, so IDK. I'm taking a guess that the esc is the problem but can't see how I smoked after running for only 45 secs. It's 3s capable and I'm running on 2s, and for the 2 days prior that I ran it I had no issues. Nothing got hot even after 30 mins of runtime so I'm really lost. I wish I had a spare sensored motor or esc laying around so I could figure out the culprit but looks like I'm just gonna suffer through the HK 8 month return process for both.

Edit: Doing some looking around, does anyone think a 60a ESC is too low for this setup on 2s? Was looking at tekin's esc and they seem to be 180amps or higher. Perhaps I did somehow fry the esc.

[DTB1]

Could it possibly be the sensor wire causing your issue. I once thermal'd a motor in 25 seconds, it baffled me for a while. Then swapped out the sensor wire and had no issues.

[Eric0424]

Personally I wouldn't put a 60 amp ESC in anything, but that's me. Some seem to do just fine with them. It's possible the 4000kV (8.5) motor in the Wraith with a fully locked drivetrain was more than the ESC could handle. If I'm looking at the correct ESC and motor from Hobby King, 8.5 turn is the max on 2S in a 4x4. They don't have a manual, just a download of Hobby Wings manual so the specs are from it.

I would try a new sensor cable, then give one of the sensorless motors you have a shot. If you get the same or similar results, then the ESC is most likely defective. With $30(ish) ESC's and motors you'll have frequent defects, they may run okay for days, weeks or even months but some will fail without warning and for no apparent reason. It's just the nature of budget electronics.

[stingeragent]

I'll agree with you there. Most of my cheapo electric experience is in relation to plane/heli stuff. The great thing about those is you can hook up a watt meter and see your amp draw with the prop on. Hard to see amp draw on a truck, because even if you ran it with the tires on and everything, it still wouldn't give you an "under load" reading unless you were running along side the truck trying to see the meter. This motor works fine if I pull the sensor cable and run it sensorless but that does me no good in a crawler. I think my gut is telling me it's the esc. I frequently checked the motor during all my runs and always was just warm so I really don't think the motor is bad although the last 2 times I took it apart it may be now (whoops). I'm going to order a 120a turnigy trackstar esc and new sensor cable. Hook it up and see what happens. I bought this set as a combo so if I return it, will have to send it all back. Want to check first before I return it to try and narrow down the problem. With a new esc, and cable, if it still doesn't work it pretty much guarantees the motor is at fault. Will have wasted the money on a new esc at that point but I guess it won't be a bad thing to double my amp capacity either way.

[novarider]

Unplug the servo and see if you still have the same problem.

[stingeragent]

Unplugged and same issue.

[OSRC]

I run 35A esc's, 17.5t motors on 2S in my SCX10 and several of my larger 2.2 trucks. They run cool all day long as long as they are geared correctly. I would have guessed ESC myself based on what you were saying....that's a tricky one though.

[stingeragent]

Ok, so I ordered a 120a turnigy esc which came in today. Realized my soldering iron is crap as it would no longer melt solder, so I had to order a 60watt soldering station. Got on with livechat at HK and uploaded a video. They assume the motor is bad which I assume it's not, and so they are sending me a replacement trackstar motor which is better than the one I ordered in the first place. So will get a new motor in next week which I guess will be a spare. I had already ordered the replacement esc so I decided not to argue with the guy about getting a better motor. New soldering iron will be in on mon so I can 100% know if it was the motor or esc that was bad. I had ordered an extra sensor cable with the new esc and tried it so I know it's not that

[Eric0424]

With a new motor, ESC and solder station you'll certainly be able to find out which one has given up the ghost. I'm still on the fence between the ESC and motor being the cause. Generally when you have to give a motor a nudge to get moving it's the motor, but the behavior it displays after trying to use reverse seems like the ESC is at fault. Of course it could be that both went south at the same time, I've seen that happen a few times. One fails and causes the other to fail with it. Whichever the case, with a new system you'll still be ready to go.

I've got a Reedy 540 Sonic that was bought used with a bad sensor board, to look at it you would swear it was nearly new. There's no visible damage to anything on the board, the hall sensors and IC's look fine even under 10 power magnification. But the RX8 Gen 2 verified a bad sensor board. Sometimes the sensors and IC's just go bad inside and don't leave a trace.

[stingeragent]

Yea. I will be glad to finally figure out which the culprit is. I had a sensorless venom system do the same thing to me about 4 years ago on a stampede. Bought it from the LHS so I just returned the whole setup. I'm not a motor expert but I can't see the motor being the cause for reverse not working. I also don't get why after running it pretty hard 2 days in a row doing 30 min sessions each and no issues, and then day 3 it doesn't last 45 secs. I do know without a doubt I hate soldering to motor tabs. It could be my crappy iron and it will be a piece of cake. Tis frustrating though cause I waited a week for the new esc and now my soldering iron decides to crap out. I'm halfway tempted to throw the stock brushed system in it just so I can drive it until the replacement comes in but I had planned to sell it so idk.

[stingeragent]

Oh the plot thickens. So I got my new soldering iron in, and it still wouldn't heat up the existing solder joint. Tried rubbing some flux on it and still wasn't working great. Anyways I just decided screw it and soldered on the remaining 2 wires. Turned everything on and attempted to calibrate the new esc. Just would not calibrate, only gave me flashing lights. ( i was using the new sensor cable I just got), anyways I hooked up the previous sensor cable and sure enough no problems, except now the esc won't see my throttle range so it won't calibrate. So then I rebinded my radio as steering wasn't working and still nothing. So I move the motor and esc over to my stampede and hook it up to its receiver and try to calibrate. Calibrates fine but of course the motor still won't turn. Move it all back over to the crawler , replug everything in and nothing. So then i'm like screw this and just solder on a battery connector to the brushed setup and plug it all in. Steering works, but still no throttle. So for giggles I move the throttle servo lead to ch1 which is steering and turn it back on, and now I can make the motor work with the steering knob so apparently CH2 went out on my axial RX. So I now need a new receiver, and I still can't run the truck. So frustrating. I am glad now though that HK sent out a replacement motor.

[Eric0424]

I know the frustration. I've had projects just nag me to death with one odd quirk after another. Receivers don't often go bad, I haven't had one quit yet, but it does happen and it's usually one of the last things you consider.

As for the solder, if it's was melted with a lot of heat the first time, it may take the same heat to melt it a second time. I had this problem back in the brushed motor days. I used a pistol style solder gun (300watts) to install the motor wires, but tried to use a portable soldering iron to change them in the field. The little butane iron just didn't have the power to melt the solder.

[stingeragent]

I've been using solder from walmart. I know most solders are 50/50, or 60/40. I was kinda curious what mine is so I went to wally world today, and the one I've been buying is like 97/3 or something like that. Could that be a problem? I think I may have damaged the 2nd esc while trying to solder on those wires with the old iron. Literrally had to hold the iron against the post for 30 secs to get it to heat up after pre-tinning it. Anyways, in my frustration last night I broke down and ordered a MMP. When the new motor comes in, i'm going to solder bare leads to it, and hook it up to the 2nd esc temporarily just to see if I somehow fried it with the crappy iron, but I'm just gonna use the MMP either way. Now that I know for sure the rx ch2 is no good, for all I know, that was the problem in the first place and there was no problem with the original hk esc and motor. Mind boggling. I've got about 340 receivers under my belt over the duration of my r/c hobby and I've never had one go bad and that's including the 6 dollar orange rx, flysky, etc. The other possibility , the RX was fine, but then when either the motor, or esc went out, it sent a voltage spike or something to ch2 on rx.

[Eric0424]

At 97/3 or 95/5 sounds like lead free plumbers solder, it does have a higher melting point due to the missing lead and it's not great for electronics. So it's probably not helping. With 30 seconds and low watt and/or weak solder iron you may not have damaged the ESC. Main reason for just few seconds is the heat that can build up, but if the iron can't melt the solder it's unlikely to damage the ESC.

Standard 60/40 and 63/37 and the silver solders are much better for our uses, but the silver solder is more expensive and a little harder to solder than 60/40 and 63/37. I've been using TrakPower, Novak and Radio Shack silver solders for my RC and other high power electronics.

I prefer and recommend the silver solders (better/higher conductance and better/lower resistance), but the 60/40 electronics works okay. I have a spool of Kester 60/40 High-Tech/Electronics for most electronics, but I use the silver in high-power, low-loss applications (motor, battery and ESC connections).